But the Bourbon restoration was not secure, Napoleon escaped Elba and made his way to Paris at Grenoble troops sent to stop him had defected.

By the time Ney arrived in Besançon, he found that the royalist position was rapidly deteriorating and that Bourmont's assignment was to spy on him.

Ney decided to read a proclamation sent to him by Napoleon, Bourmont and Lecoube did not agree but did give it sanction of their presence.

[1] According to historian David Hamilton-Williams, the Comte d'Artois asked Bourmont to remain a royalist agent, so he requested to continue in command.

The new Minister of War, Marshal Davout refused to employ Bourmont, writing to Napoleon, "I cannot sit idly and watch this officer wear the uniform of this country; his treasonous statements concerning the Emperor are well known to all; the brigade and regimental commanders of the 14th Infantry Division despise him.

[2] On the morning of the 15th of June, as the French Army of the North advanced into Belgium, the 14th Division led the IV Corps column of march.

In the missive, he explained that he was deserting but promised, "They will not get any information from me which will injure the French army, composed of men I love."

Étienne Hulot, who became the acting division commander, was compelled to give a speech that pledged loyalty to Napoleon and the tricolor.

[4] The most controversial part of Bourmont's testimony was his statement that; Marshal Ney, was so thoroughly resolved beforehand to take the side of Bonaparte, that half an hour after reading the proclamation he was wearing the Grand Eagle of the Legion of Honour with the effigy of the usurper.If true this statement would undermine Ney's defence that he only changed sides out of necessity and to prevent needless loss of French lives in a civil war.

When examined about if resistance by Ney was possible given the difference in numbers of troops, Bourmont replied that;[4] Everything depended on the first step, if he had taken a carbine and fired the first shot, no doubt his example would have been decisive, for no man had a greater empire over the minds of the soldiers.Latter testimony given by Lecourbe before his death was read, that partially contradicted Bourmont suggesting that there was no prospect for resistance, and that even in the absence of the proclamation the troops would likely have defected in any case.

After the Second Restoration, he was given command of the 16th infantry division in Besançon and took part in the Spanish campaign of 1823 where he won the battle of Sanlucar[4], and took Seville.

King Charles X of France made him minister of war in 1829 and in 1830 was appointed commander of forces mustering to invade Algeria.

[5] But in his absence the July Revolution overthrew Charles X. Bourmont refused to give his allegiance to the new King Louis Philippe and was replaced by Bertrand Clauzel as commander in Algeria.

Bourmont hoped to lead his army back to France in the name of Charles but lacking support amongst the rank and file he went into exile in Spain.

[5] In 1832 Marshal Bourmont took part in the rising of Caroline Ferdinande Louise, duchesse de Berry and on its failure fled to Portugal.

He commanded the army of the absolutist monarch King Miguel during the Liberal Wars and after the victory of the constitutional party he retired to Rome.